The present invention relates to computer animation. More particularly, the present invention relates to a method, apparatus and computer program for transferring motion behavior from traditionally animated cartoons to other digital characters and media.
Animation can be thought of as having two dimensions: the visual style (how the image looks, how it is rendered, the style of the drawing or model) and the motion style (how the characters move, the amount of exaggeration, use of cartoon physics and way in which the animation principles are used). The visual style of an animation can be anything from photo-realistic to abstract. The motion style also varies from one animation to another. It can range from robotic, to realistic to highly expressive.
Physical simulation and motion capture have been fairly effective for creating realistic motion. Physical simulation techniques are mainly used to create low-level physical phenomena and motion capture is used to create realistic human motions.
Physical simulation is a technique for replicating physical phenomena on a laboratory scale in such a way that the resultant data can be used for creating animated motion. Motion capture is a technique for creating animated motion by recording the motion of a live human or animal. The resultant data from physical simulation and the recorded data from motion capture are fit with a three-dimensional kinematics model, and the model is used to drive the behavior of a cartoon character. A key problem with both physical simulation and motion capture is that the derived behavior is typically not nearly as expressive as motion created by highly skilled traditional animators. Thus, the resulting characters appear lifeless and robotic.
Traditional animation is created by highly trained animators who use animation principles to create motion that is expressive and stylized. Often this motion includes exaggeration, cartoon physics and extra degrees of freedom in joint motion. However, stylized and expressive animation, as done by traditional animators, can be time consuming or even impossible. Skilled artists are rare and the costs for employing such individuals are often prohibitive. Further, at present traditionally drawn animations cannot be easily re-used or transferred to different domains and characters.
Therefore, a need exists for generating highly stylized and expressive animation of the level produced by traditional animators. Further, a need exists for easily re-using or transferring motion previously developed for a cartoon to different domains and other characters.